noverlap
v5.2.1
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dependency-less-ly prevent function invocations (both sync and async) from redundantly overlapping with each other
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noverlap
dependency-less-ly prevent function invocations (both sync and async) from redundantly overlapping with each other
usage
first import noverlap
yarn add noverlap
import noverlap from 'noverlap';
then instantiate a noverlap
instance
const throttle = noverlap();
or instantiate noverlap
with custom configurations:
hash
: a function that generate a hash given the wrapped function's argumentscomparator
: a function that determines whether or not a hash has already been added as a key when looking through the map's keys. useful for when you've lost the reference to certain keys (eg storing objects or arrays as keys). defaults to thesameValueZero
algorithm which is used byMap.prototype.has
wait
: the timer duration in milliseconds that will start on each execution of an async function and reset with every overlapping executionstart
: a callback (provided with the wrapped function's arguments) that will be synchronously executed right before the wrapped functionqueue
: a callback that gets fired when a function execution has been added to the queue that will be eventually flushedbeforeFinish
: a callback that gets fired right before the wrapped function finally gets called and the queue gets flushedsuccess
: a callback that gets fired when the redundantly invoked function was resolvedfail
: a callback that gets fired when the redundantly invoked function was rejectedfinish
: a callback (provided with the return value of the wrapped function) that will be fired after the wrapped function
the following are the default configurations:
const defaultThrottle = noverlap({
/** the first parameter will be considered the hash of the function execution */
hash: (...args) => args[0],
/** find a direct reference to the hash that will be looked up as the key in map.get(key) */
comparator: (hash, existingKey) => { /* 'SameValueZero' algorithm */ },
/** wait 420ms to see if another execution of the async function is overlapping with an existing one */
wait: 420,
})
the following are not included by default but can be added manually during noverlap
instantiation (these manual additions get merged with the default configurations)
const customThrottle = noverlap({
start(payload) { console.log('a function has just been hashed', payload) },
beforeFinish(payload) { console.log('about to execute the function with a payload of', payload) },
finish(returnValue) { console.log('the redundantly invoked function returned', returnValue) },
});
you can also use a function or promise that is provided with the wrapped function's parameters to construct a noverlap
instance's configs
const throttle = noverlap((...args) => /* noverlap configs */);
const throttle = noverlap(async (...args) => /* noverlap configs */);
let's use this dummy async function that we pretend makes a fetch to a server. we do not want this fetcher to make the same call multiple times in a row when in fact we only need the data from the latest call, which should return the most up to date response
const dummyFetcher = payload => new Promise((resolve, reject) => setTimeout(() => resolve(payload)));
apply the noverlap instance to an async function by wrapping it
const throttle = noverlap();
const fetchSomeData = throttle(async payload => {
const response = await dummyFetcher(payload);
console.log('this async function will only be executed once even if it is called with the same payload multiple times within 420ms');
return response;
});
now, using fetchSomeData
like this:
const redundantAsyncExecution = async n => console.log(
`result from execution #${n} with a redundantly repeated fetch using ${
await fetchSomeData('this payload')
} 🤯`
);
redundantAsyncExecution(1);
redundantAsyncExecution(2);
redundantAsyncExecution(3);
will log:
this async function will only be executed once even if it is called with the same payload multiple times within 420ms
result from execution #1 with a redundantly repeated fetch using this payload 🤯
result from execution #2 with a redundantly repeated fetch using this payload 🤯
result from execution #3 with a redundantly repeated fetch using this payload 🤯